[PATCH v9 4/6] dt-bindings: anybus-controller: document devicetree binding

From: Sven Van Asbroeck
Date: Mon Mar 18 2019 - 14:03:59 EST


This patch adds devicetree binding documentation for the
Arcx anybus controller.

Signed-off-by: Sven Van Asbroeck <TheSven73@xxxxxxxxx>
---
.../fieldbus/arcx,anybus-controller.txt | 71 +++++++++++++++++++
1 file changed, 71 insertions(+)
create mode 100644 Documentation/devicetree/bindings/fieldbus/arcx,anybus-controller.txt

diff --git a/Documentation/devicetree/bindings/fieldbus/arcx,anybus-controller.txt b/Documentation/devicetree/bindings/fieldbus/arcx,anybus-controller.txt
new file mode 100644
index 000000000000..b1f9474f36d5
--- /dev/null
+++ b/Documentation/devicetree/bindings/fieldbus/arcx,anybus-controller.txt
@@ -0,0 +1,71 @@
+* Arcx Anybus-S controller
+
+This chip communicates with the SoC over a parallel bus. It is
+expected that its Device Tree node is specified as the child of a node
+corresponding to the parallel bus used for communication.
+
+Required properties:
+--------------------
+
+ - compatible : The following chip-specific string:
+ "arcx,anybus-controller"
+
+ - reg : three areas:
+ index 0: bus memory area where the cpld registers are located.
+ index 1: bus memory area of the first host's dual-port ram.
+ index 2: bus memory area of the second host's dual-port ram.
+
+ - reset-gpios : the GPIO pin connected to the reset line of the controller.
+
+ - interrupts : two interrupts:
+ index 0: interrupt connected to the first host
+ index 1: interrupt connected to the second host
+ Generic interrupt client node bindings are described in
+ interrupt-controller/interrupts.txt
+
+Optional: use of subnodes
+-------------------------
+
+The card connected to a host may need additional properties. These can be
+specified in subnodes to the controller node.
+
+The subnodes are identified by the standard 'reg' property. Which information
+exactly can be specified depends on the bindings for the function driver
+for the subnode.
+
+Required controller node properties when using subnodes:
+- #address-cells: should be one.
+- #size-cells: should be zero.
+
+Required subnode properties:
+- reg: Must contain the host index of the card this subnode describes:
+ <0> for the first host on the controller
+ <1> for the second host on the controller
+ Note that only a single card can be plugged into a host, so the host
+ index uniquely describes the card location.
+
+Example of usage:
+-----------------
+
+This example places the bridge on top of the i.MX WEIM parallel bus, see:
+Documentation/devicetree/bindings/bus/imx-weim.txt
+
+&weim {
+ controller@0,0 {
+ compatible = "arcx,anybus-controller";
+ reg = <0 0 0x100>, <0 0x400000 0x800>, <1 0x400000 0x800>;
+ reset-gpios = <&gpio5 2 GPIO_ACTIVE_HIGH>;
+ interrupt-parent = <&gpio1>;
+ interrupts = <1 IRQ_TYPE_LEVEL_LOW>, <5 IRQ_TYPE_LEVEL_LOW>;
+ /* fsl,weim-cs-timing is a i.MX WEIM bus specific property */
+ fsl,weim-cs-timing = <0x024400b1 0x00001010 0x20081100
+ 0x00000000 0xa0000240 0x00000000>;
+ /* optional subnode for a card plugged into the first host */
+ #address-cells = <1>;
+ #size-cells = <0>;
+ card@0 {
+ reg = <0>;
+ /* card specific properties go here */
+ };
+ };
+};
--
2.17.1